This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2000-214510, filed Jul. 14, 2000, the entire contents of both of which are incorporated herein by reference.
1. Field of the Invention
The present invention is related to slurry for CMP used in the field of semiconductor device manufacturing, a method of forming the slurry and a method of manufacturing semiconductor device including a CMP process.
2. Description of the Related Art
Recently, in the field of semiconductor device manufacturing, various microfabrication technologies have been developed as integration of semiconductor device increases and size of semiconductor element decreases. Among the microfabrication technologies, CMP technology has become an essential technology for a formation of damascene wiring.
When forming the damascene wiring with metal CMP, the most important subject is to prevent an occurrence of erosion and avoid causing scratch. For preventing such erosion, it is required to use a hard polishing cloth and a slurry for CMP, (hereinafter simply referred to as xe2x80x9cslurryxe2x80x9d) having the margin for over polishing.
For expanding the margin against the over polishing, it is a key factor to efficiently transfer a change in loading to a metal film as a substrate to be polished. CMP property giving high dependence of the loading on the polishing rate, i.e., the polishing rate sensitively responds to the change in the loading, is desired.
As a method to realize such CMP property, it is effective to use a slurry containing an organic particle and a plurality of inorganic particles in an unified state as polishing particles. This method is to cohere inorganic particles around an organic particle having no polishing performance to use the organic particle as an assist particle for the inorganic particles.
By using such slurry described above, the change in the loading is efficiently transferred to the substrate to be polished by the elasticity of the organic particle, thereby increasing the dependency of the polishing rate on the loading, and also, the elasticity can avoid the scratching which is caused by using a hard polishing cloth.
It is an object of the present invention to provide a slurry effective to realize CMP having property of low erosion and high margin against over polishing, a method of forming the slurry and a method of manufacturing a semiconductor device having CMP process capable of realizing CMP with low erosion and high margin against over polishing.
In order to achieve the object of the present invention described above, the first aspect of the present invention includes a slurry for CMP comprising: a liquid; and a plurality of polishing particles contained in the liquid, the polishing particle comprising at least one organic particle and at least one inorganic particle, and the organic particle and the inorganic particles being formed unified by thermocompression bonding.
The second aspect of the present invention includes a method of forming a slurry for CMP comprising: mixing a plurality of organic particles with a plurality of inorganic particles in powder state and with use of mechanofusion phenomenon, unifying at least one of the plurality of organic particles and at least one of the plurality of inorganic particles, to forme a plurality of polishing particles; and adding the polishing particles into a liquid.
The third aspect of the present invention includes a method of manufacturing a semiconductor device comprising: forming a conductive film above a substrate; and polishing the conductive film by using a slurry for CMP, the slurry including a plurality of polishing particles, the polishing particle comprising at least one organic particle and at least one inorganic particle, and the organic particle and the inorganic particles being unified by thermocompression bonding.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.